Dual chamber pumps have been suggested in U.S. Pat. Nos. 3,255,935; 4,323,176; 4,413,759; 4,461,403; 4,487,341; 4,643,337; 4,673,106; 4,691,847; and 4,775,080.
Among the objectives of the present invention are to provide a dual chamber pump package for viscous products which efficiently dispenses viscous products from separate chambers; wherein by manual manipulation of a single lever balanced regulated amounts are dispensed from both chambers even when the chambers have differing diameters; wherein after dispensing when the lever is released, pistons in each chamber are held in a newly elevated position; wherein the pump package includes a minimum number of parts.